I think Noel is right, it is an activation issue because Sonar is now telling me that I'm running it in demo mode and my subscription has expired. (It hasn't -- I paid up on 2/23.) I just installed the Braintree update again and instead of crashing after 10 seconds it pops up a notification saying that it's in demo mode. It appears to have been a coincidence that it didn't start having problems with activation until just after installing the Anderton update. (Though you can still be a badass killer if you want to, Craig.)
Hopefully I can get it worked out with Cakewalk support this week. Thanks for your help guys. :)